Introduction
SharePoint has transformed from an on-premises collaboration portal to a cloud-based, low-code digital workplace integrated deeply into Microsoft 365. With this transformation, the customization model has evolved, moving from server-side solutions to client-side (SPFx), Power Platform integration, and PnP provisioning.
This article explores all major SharePoint customization options, their capabilities, limitations, and which areas remain non-customizable in the modern experience.
Types of SharePoint Customization
| Type | Technology / Tools | Scope | Supported In |
|---|
| Out-of-the-Box Configuration | Site settings, List views, JSON formatting | Basic UI and list customization | Modern + Classic |
| SPFx (SharePoint Framework) | React, TypeScript, REST API | Web parts, extensions, app customizers | Modern |
| Power Platform Integration | Power Apps, Power Automate, Power BI | Forms, workflows, dashboards | Modern + Classic |
| PnP Scripting / Provisioning | PnP PowerShell, CLI for M365 | Site templates, provisioning automation | Modern + Classic |
| Branding & Theming | JSON theme, site header/footer | corporate design consistency | Modern |
| Classic Server-Side Customization | Master pages, .WSP, Farm Solutions | Full control (Legacy only) | Classic only |
1. Out-of-the-Box (OOTB) Customization
Best For: No-code configuration of lists, libraries, and navigation.
You can
Configure lists, libraries, and metadata.
Use JSON to format views and columns.
Adjust site navigation and permissions.
Apply OOTB site templates (Team / Communication).
You cannot
Example
Use JSON view formatting to convert a list into a visually appealing card grid.
2. SharePoint Framework (SPFx)
Best For: Modern UI web parts, extensions, and deep integration.
You can
Build custom React-based web parts.
Create Application Customizers for headers/footers.
Use Field Customizers for special column rendering.
Add Command Sets to list toolbars.
Integrate with Microsoft Graph and REST APIs.
You cannot
Override or replace Microsoft-managed page layouts.
Modify core system pages (e.g., settings or permissions pages).
Change suite navigation or modern shell components.
Example
A dashboard web part that pulls live metrics from Power BI or Azure DevOps using Graph API.
3. Power Platform Integration
Best For: Rapid automation, form customization, and business processes.
| Component | Purpose | Integration with SharePoint |
|---|
| Power Apps | Custom forms & mobile apps | Replace SharePoint list forms |
| Power Automate | Workflows & process automation | Trigger on item create/update |
| Power BI | Analytics and reporting | Embed dashboards in pages |
Limitations
Power Apps cannot alter the site UI beyond forms.
Flow triggers depend on available connectors.
Power BI embedding requires licensing and permissions.
4. Branding & Theming
Best For: Corporate look and feel consistency.
You can
Apply JSON-based site themes via PowerShell.
Modify site headers, footers, and logos.
Use Fluent UI elements in SPFx for design consistency.
You cannot
Example
Apply a corporate theme
5. Legacy Server-Side Customization (Classic Only)
Applies To: On-premises or Classic SharePoint Online.
You can
Modify master pages and page layouts.
Use custom server controls and event receivers.
Deploy .WSP or Sandbox solutions.
Limitation
These are deprecated in SharePoint Online. Microsoft now discourages custom master pages or JS injection in modern sites for security and maintainability reasons.
Modern vs Classic Customization — Comparison
| Feature | Classic SharePoint | Modern SharePoint |
|---|
| Master Page Editing | Supported | Deprecated |
| JavaScript Injection | Allowed | Restricted |
| SPFx Support | Not available | Fully supported |
| Power Platform Integration | Partial | Deep integration |
| Branding | Master Page / CSS | JSON Theme / Header/Footer |
| Custom Forms | InfoPath / ASPX | Power Apps |
| Workflows | SharePoint Designer / Nintex | Power Automate |
| Provisioning | Feature XML / Sandbox | PnP, CLI for M365 |
| Deployment | Farm/Sandbox solutions | SPFx Packages, PnP Templates |
| Performance & Updates | Manual | Evergreen (Microsoft-managed) |
Non-Customizable Areas in Modern SharePoint
| Area | Restriction | Reason |
|---|
| System Pages (Permissions, Site Settings) | Cannot inject scripts or modify | Security boundary |
| Modern Page Layouts | Not editable at structure level | Microsoft-managed UX |
| Document Library Core View | Only JSON formatting | Consistency & performance |
| Suite Navigation (M365 Header) | Non-customizable | Unified M365 experience |
| Microsoft Search Page | Only Configurable | Centralized search control |
| Syntex & Viva Components | Configuration Only | Managed services |
Choosing the Right Customization Approach
| Scenario | Recommended Approach |
|---|
| Replace default SharePoint form | Power Apps |
| Automate approvals/workflows | Power Automate |
| Create dashboards or reports | Power BI |
| Add custom UI components | SPFx Web Parts |
| Modify list presentation | JSON Formatting |
| Provision new sites | PnP PowerShell / CLI for M365 |
Conclusion
The era of modifying master pages and injecting scripts is over. Modern SharePoint prioritizes security, maintainability, and cloud-readiness.